onsemi D45C8

Overview

D45C8 from ON Semiconductor is a PNP silicon power transistor designed for medium-power linear and switching amplifier applications, with -60 V V_CEO, -4.0 A continuous collector current, and 60 W total device dissipation at T_A = 25°C. It features h_FE of 40–120 at I_C = -0.2 A, f_T = 32 MHz, and R_θJC = 2.1 °C/W - enabling use in audio output stages and DC motor drivers where thermal management and gain stability are critical.

For engineers reviewing the D45C8 datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-220 package with Base–Collector–Emitter pinout, saturation voltage of -0.5 V at I_C = -1.0 A / I_B = -50 mA, and safe operating area defined by V_CEO, I_C, and thermal resistance limits.

Technical Context

The D45C8 operates as a discrete PNP bipolar junction transistor (BJT) fabricated on Fairchild's process 5P, optimized for high-current linear amplification and hard-switching duty. Its design emphasizes robust secondary breakdown immunity, low saturation voltage, and stable DC current gain across collector currents from -0.2 A to -2.0 A.

Thermal performance is defined by R_θJC = 2.1 °C/W and R_θJA = 62.5 °C/W, requiring heatsinking for sustained operation above ~10 W. Small-signal behavior includes Cob = 125 pF at V_CB = -10 V and f_T = 32 MHz, supporting audio-frequency and low-MHz switching applications.

Key Specifications

Pinout & Package

Package: TO-220 (3-lead, straight lead, insulated tab). Standard mounting requires electrically isolated heatsink interface due to collector-connected tab.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP power amplifier applications.

Compared with MJD45C and 2SA1943, the D45C8 occupies a mid-tier niche: it delivers sufficient current and gain for 10–20 W amplifiers in cost-sensitive TO-220 form, with better thermal performance than DPAK alternatives and lower system cost than oversized TO-3P devices.

Availability

D45C8 is available at Aetrix Electronics and suitable for audio power amplifiers, DC motor drivers, linear voltage regulators, and lab-grade power supply designs requiring stable component supply and long-term manufacturability.

Supply support for D45C8 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

ON Semiconductor (formerly Fairchild Semiconductor) is a global supplier of energy-efficient semiconductor components, specializing in power management, analog, and discrete devices for automotive, industrial, and consumer markets.

The D45C8 belongs to ON Semiconductor's legacy PNP power transistor family developed for linear amplification and switching applications; it was originally introduced by Fairchild to serve cost-optimized, medium-power analog systems requiring proven SOA and thermal reliability.

FAQ

What is the maximum continuous collector current rating for the D45C8?

The D45C8 has a maximum continuous collector current (I_C) rating of -4.0 A at T_A = 25°C. This rating assumes adequate heatsinking and derating per the specified 480 mW/°C above 25°C ambient. Operation near this limit requires verification of junction temperature using R_θJC = 2.1 °C/W and actual case temperature measurements. The D45C8 must not exceed its SOA limits under pulsed or transient conditions.

Does the D45C8 have a built-in base-emitter resistor or protection diode?

No, the D45C8 is a standard three-terminal PNP bipolar transistor with no integrated base-emitter resistor or protection diode. External base current limiting and flyback protection (e.g., base-emitter clamp diode) must be added per application requirements. This discrete architecture allows full design flexibility but places responsibility on the circuit designer to ensure proper drive and protection - a characteristic confirmed in the D45C8 datasheet's "Off Characteristics" and "On Characteristics" sections.

What is the pin configuration of the D45C8 in its TO-220 package?

The D45C8 uses a standard TO-220 package with leads ordered as follows when viewed from the front (flat side facing viewer, leads down): Pin 1 = Base, Pin 2 = Collector (connected to metal tab), Pin 3 = Emitter. This configuration is explicitly documented in the D45C8 Rev. B2 datasheet, page 1, and verified across ON Semiconductor's official parametric listings and distributor footprint data.

Can the D45C8 be used in parallel with another D45C8 for higher current handling?

Parallel operation of D45C8 devices is not recommended without individual emitter resistors and matched h_FE/V_BE(sat) characteristics. The D45C8 exhibits typical h_FE variation (40–120) and V_BE(sat) spread that can cause current imbalance. If parallel use is required, external 0.1–0.5 Ω emitter resistors per device and thermal coupling are mandatory - and even then, derating by ≥30% is advised. The D45C8 datasheet does not specify or endorse paralleling.

Is the D45C8 RoHS compliant and halogen-free?

Yes, the D45C8 is RoHS compliant and halogen-free per ON Semiconductor's product change notification PCN-140101 and material declarations. As a Fairchild-integrated part now managed under ON Semiconductor's quality system, the D45C8 meets JEDEC J-STD-609 Category 1 for halogen content and complies with EU Directive 2011/65/EU. Full compliance documentation is available via ON Semiconductor's website using the D45C8 part number.